From the time of Descartes a strong tendency emerged to exclude the consideration of metaphysical questions as a necessary step towards developing truly scientific disciplines. Within human geography, positivism had a significant influence in moulding the discipline as "spatial science", resulting in a reductionist vision of humanity. Since the 1970s, in reaction to the limitations of this narrow vision and also to the deterministic perspective of marxism, humanistic approaches became important, but have failed to adequately deal with the exclusion of metaphysical issues. The more recent emergence of postmodern influences within human geography, while being critical of the rigidities associated with Enlightenment thinking, and suggesting a greater tolerance of "difference", appears reluctant to reconsider the exclusion of metaphysics. This paper suggest that such a reconsideration could contribute significantly towards increasing human geography's capacity to help policy makers deal more adequately with some of the major issues facing humanity.